Regardless Of where the gas comes from, or what brand it is, Gas that is "Top Tier" has the "Top Tier" magic potion added at the actual gas station. Here's the "Top Tier" tank / injection pump at the Costco in Wilmington, NC. https://goo.gl/maps/XddnYBokp9kdruEZ9 Now, I don't see cars filing up at Sams or other gas stations and then dying because no "Top Tier" blinker fluid is in it.
As an earlier poster mentioned, Hyundai's take on Top Tier is "If TOP TIER Detergent Gasoline is not available, one bottle of additive added to the fuel tank at every 7,500 miles or 12 months is recommended."
As an earlier poster mentioned, Hyundai's take on Top Tier is "If TOP TIER Detergent Gasoline is not available, one bottle of additive added to the fuel tank at every 7,500 miles or 12 months is recommended."